Nutrient effects on a detritus-based stream ecosystem at the Coweeta Hydrologic Laboratory from 1998 to 2003

To determine the effects of nutrient enrichment in a detritus-based stream, we have continuously enriched a headwater stream with N and P for 4.5 years and quantified the response at different scales of stream structure and function: microbial, metazoan, and ecosystem. The effects of enrichment in the treatment stream (Watershed 54, WS54) were compared to conditions in the reference stream (Watershed 53, WS53) and one year of comprehensive baseline sampling was conducted in both streams prior to enrichment. Our first objective was to assess the effects of nutrient enrichment on growth and production of organisms. Our second objective was to determine the effects of nutrients on the fate of carbon resources, which were altered via increased microbial metabolism and invertebrate consumption.